HVAC: Difference between revisions

(2 intermediate revisions by one other user not shown)

Line 95:

== Heating Zones ==

~~The upstairs and the downstairs are the 2 separate heating zones.~~

~~==== Upstairs ====~~

The building has three heating zones that are separately controlled. The room in the back left corner of the main room (looking toward the back of the building) contains our boiler and our hot water tank. It is important to know that the thermostat is an on-off switch, not a valve: setting it to 90 won't heat anything up quicker, and setting it to 50 won't cool anything down quicker. Set it to the temperature you want, and let the system get there. Also, the thermostats are adjustable by anyone, so please be excellent to each other and don't fight over the temperature. System problems should be flagged to the General Operations Team for investigation: you can tag us in any message.

~~The thermostat is by the closet across from the top of the front stairs, in the craft area. The heat and cooling~~ are in the ~~closet.~~

=== Summary ===

A quick primer on heating at PS1: There are three (four) thermostats for the heating systems:

~~==== Downstairs ====~~

* The front of the 3519 building (in Lasers/3D Printing, controls heat there, Lounge, and upstairs) - forced air

* The back of the 3519 building (by the Clausing lathe, controls heat for General, Cold Metals, Small Metals, the Kitchen, and sort of controls the Catwalk although the servers heat that more),

* The 3517 building (by the radial arm saw, controls heat for Wood Shop and Hot Metals). They are all user-adjustable and they control the hot water pumps for the various radiators and heating units. The heating units in the workshop areas are self-controlled: the blowers will come on when the heating coils are hot enough to matter, and will shut off when they cool off enough. The thermostat controls the supply of hot water to the units, so they won't turn on right away when the thermostat is turned up.

* Besides these, there is a fourth thermostat in Arts that controls only that furnace. That one is locked, and it's only meant to provide heat when the hot water system isn't.

~~The room in the back left corner of the main room (looking toward the back of the building) contains our boiler and our hot water tank.~~

=== Upstairs ===

The ~~thermostat~~ is ~~located in~~ the ~~metal shop area~~. The ~~non-functioning wifi thermostat was replaced by a "dumb"~~ thermostat in the ~~fall of 2014~~. ~~This~~ thermostat ~~controls~~ heat in the ~~shop area~~.

The first zone is a hot-water circuit from the "north-side" boiler (the larger one at the back of the boiler room) serving the back stairs, the 3D/Lasers Room, the Lounge, and the upstairs areas (Electronics and Arts). The thermostat for this zone is in the 3D/Lasers room and controls the circulator for this circuit. Note that turning on the thermostat in the 3D room will also heat the upstairs. Although the radiators upstairs are controlled by a thermostatic valve, this doesn't seem to work well and it's possible to overheat the upstairs, especially if the 3D room's windows are open to provide makeup air to the lasers.

~~The front room~~ has ~~a thermostat near~~ the ~~safe~~. ~~This system~~ is ~~independently controlled~~ by the ~~same boiler system~~ in the ~~boiler room~~. ~~This thermostat ALSO controls radiator pipes upstairs. Setting the thermostat high~~ in the ~~lounge can make the upstairs area very warm, be aware~~.

Upstairs also has forced-air heat, separate from the rest of the space. The thermostat is by the closet across from the top of the front stairs, in the craft area. The heat (and cooling) are in the closet.

==== ~~Shop~~ ====

=== North Shop ===

The second zone is also served from the "north-side" boiler on a second hot water circuit. This circuit feeds the four unit heaters in the north shop (General, Cold Metals, and Small Metals). The unit heaters are set up so that they will not start until the water going through them reaches a certain temperature. For this reason, it will take a while (sometimes hours) for them to start when the thermostat is turned on.

The thermostat is located in the Cold Metals area near the lathes. The non-functioning wifi thermostat was replaced by a "dumb" thermostat in the fall of 2014. This thermostat controls the circulator for this area. This is a totally separate thermostat from the air conditioner thermostat (near the breaker panels).

This hot water circuit has a high point air bleeder valve near the unit heater over the kitchen and at least one low point drain in the kitchen under the sink.

==== Trouble History ====

Around the end of December 2015 the heat in the shop stopped working. the boiler, thermostat and the circulating pump all seemed in working order. Most likely cause was determined to be an 'air lock' preventing circulation. There is a valve at the high point of the piping, it's at the heat exchanger above the kitchen just north of the door to the shop. The boiler was switched off, a hose was run from the valve to the kitchen sink and the valve was opened. Nothing happened. The gauge on the boiler showed 12 psi and it was expected that the automatic makeup water valve would open and add water to the system forcing any trapped air out. This did not happen. Water was added manually until a steady flow was draining into the kitchen sink. The air bleed valve was closed and the system was turned back on. The system was run until all four heat exchangers in the shop came on. Then the process was repeated and more air was purged. It was also noted that prior to starting the process that the expansion tank was empty although the boiler was hot. The system was left running with a boiler pressure of 18psi and the expansion tank about 1/8 full.

* It may be that the automatic make up water valve is defective or set to come on below 12 psi and it also may be that the static pressure at the valve is about 12 psi with another valve open to atmosphere.

=== South Shop ===

There is a second, smaller boiler, with a second feed valve, expansion tank, and circulating pump, for the south shop (Woods/Hot Metals). The boiler is on the opposite wall from the first (north shop) boiler. The hot water circuit from this boiler feeds two unit heaters, one in the Wood Shop and one in Hot Metals. Again, these will not switch on until the water going through is hot enough. This circuit usually heats up fairly quickly, though.

The thermostat for this zone is in the middle of the Wood Shop, right next to the (separate) air conditioner thermostat.

== Outside air exchange ==

Line 158:

Line 175:

== Maintenance ==

Some of our HVAC systems require regular maintenance.

[[File:Boiler-1-feed.png|200px|thumb|left|The water supply arrangement on the boiler for the north shop.]]

==== Water Level ====

The boilers are connected to the incoming water supply in the usual way, with pressure reducing valves. The PRV for the south-side boiler has a bypass lever on it, which can be pulled up to force water in, but it is supposed to add water automatically if needed. This lever should only be pulled up for major service, like flushing the system, or if the PRV doesn't work for some reason.

The north-side boiler's pressure reducing valve doesn't have a bypass lever. Instead, it has a separate bypass valve that can be opened to fill the boiler. As of December 2020, the PRV doesn't seem to work correctly and may need to be adjusted. If water needs to be added to the system, open the green valve under the PRV until it is topped up. Cold pressure in both boilers should be about 12 psi.

==== Pumps ====

In the boiler room the two red pumps that force hot water for radiant heat in the front room and the shop area. These pumps have three ports for oil lubrication. The two ports on either side of the pump get 3 drops of oil each, the covered port over the bearing needs one strong squirt. This needs to be done annually. This was last performed ~~2018~~-01-14.

In the boiler room the two red pumps that force hot water for radiant heat in the front room and the shop area. These pumps have three ports for oil lubrication. The two ports on either side of the pump get 3 drops of oil each, the covered port over the bearing needs one strong squirt. This needs to be done annually. This was last performed 2020-10-29.

==== Filter ====

@@ Line 95: / Line 95: @@
 == Heating Zones ==
-The upstairs and the downstairs are the 2 separate heating zones.
-==== Upstairs ====
+The building has three heating zones that are separately controlled. The room in the back left corner of the main room (looking toward the back of the building) contains our boiler and our hot water tank. It is important to know that the thermostat is an on-off switch, not a valve: setting it to 90 won't heat anything up quicker, and setting it to 50 won't cool anything down quicker. Set it to the temperature you want, and let the system get there. Also, the thermostats are adjustable by anyone, so please be excellent to each other and don't fight over the temperature. System problems should be flagged to the General Operations Team for investigation: you can tag us in any message.
-The thermostat is by the closet across from the top of the front stairs, in the craft area. The heat and cooling are in the closet.
+=== Summary ===
+A quick primer on heating at PS1: There are three (four) thermostats for the heating systems:
-==== Downstairs ====
+* The front of the 3519 building (in Lasers/3D Printing, controls heat there, Lounge, and upstairs) - forced air
+* The back of the 3519 building (by the Clausing lathe, controls heat for General, Cold Metals, Small Metals, the Kitchen, and sort of controls the Catwalk although the servers heat that more),
+* The 3517 building (by the radial arm saw, controls heat for Wood Shop and Hot Metals). They are all user-adjustable and they control the hot water pumps for the various radiators and heating units. The heating units in the workshop areas are self-controlled: the blowers will come on when the heating coils are hot enough to matter, and will shut off when they cool off enough. The thermostat controls the supply of hot water to the units, so they won't turn on right away when the thermostat is turned up.
+* Besides these, there is a fourth thermostat in Arts that controls only that furnace. That one is locked, and it's only meant to provide heat when the hot water system isn't.
-The room in the back left corner of the main room (looking toward the back of the building) contains our boiler and our hot water tank.
+=== Upstairs ===
-The thermostat is located in the metal shop area. The non-functioning wifi thermostat was replaced by a "dumb" thermostat in the fall of 2014. This thermostat controls heat in the shop area.
+The first zone is a hot-water circuit from the "north-side" boiler (the larger one at the back of the boiler room) serving the back stairs, the 3D/Lasers Room, the Lounge, and the upstairs areas (Electronics and Arts). The thermostat for this zone is in the 3D/Lasers room and controls the circulator for this circuit. Note that turning on the thermostat in the 3D room will also heat the upstairs. Although the radiators upstairs are controlled by a thermostatic valve, this doesn't seem to work well and it's possible to overheat the upstairs, especially if the 3D room's windows are open to provide makeup air to the lasers.
-The front room has a thermostat near the safe. This system is independently controlled by the same boiler system in the boiler room. This thermostat ALSO controls radiator pipes upstairs. Setting the thermostat high in the lounge can make the upstairs area very warm, be aware.
+Upstairs also has forced-air heat, separate from the rest of the space. The thermostat is by the closet across from the top of the front stairs, in the craft area. The heat (and cooling) are in the closet.
-==== Shop ====
+=== North Shop ===
+The second zone is also served from the "north-side" boiler on a second hot water circuit. This circuit feeds the four unit heaters in the north shop (General, Cold Metals, and Small Metals). The unit heaters are set up so that they will not start until the water going through them reaches a certain temperature. For this reason, it will take a while (sometimes hours) for them to start when the thermostat is turned on.
+The thermostat is located in the Cold Metals area near the lathes. The non-functioning wifi thermostat was replaced by a "dumb" thermostat in the fall of 2014. This thermostat controls the circulator for this area. This is a totally separate thermostat from the air conditioner thermostat (near the breaker panels).
+This hot water circuit has a high point air bleeder valve near the unit heater over the kitchen and at least one low point drain in the kitchen under the sink.
+==== Trouble History ====
 Around the end of December 2015 the heat in the shop stopped working. the boiler, thermostat and the circulating pump all seemed in working order. Most likely cause was determined to be an 'air lock' preventing circulation. There is a valve at the high point of the piping, it's at the heat exchanger above the kitchen just north of the door to the shop. The boiler was switched off, a hose was run from the valve to the kitchen sink and the valve was opened. Nothing happened. The gauge on the boiler showed 12 psi and it was expected that the automatic makeup water valve would open and add water to the system forcing any trapped air out. This did not happen. Water was added manually until a steady flow was draining into the kitchen sink. The air bleed valve was closed and the system was turned back on. The system was run until all four heat exchangers in the shop came on. Then the process was repeated and more air was purged. It was also noted that prior to starting the process that the expansion tank was empty although the boiler was hot. The system was left running with a boiler pressure of 18psi and the expansion tank about 1/8 full.
 * It may be that the automatic make up water valve is defective or set to come on below 12 psi and it also may be that the static pressure at the valve is about 12 psi with another valve open to atmosphere.
+=== South Shop ===
+There is a second, smaller boiler, with a second feed valve, expansion tank, and circulating pump, for the south shop (Woods/Hot Metals). The boiler is on the opposite wall from the first (north shop) boiler. The hot water circuit from this boiler feeds two unit heaters, one in the Wood Shop and one in Hot Metals. Again, these will not switch on until the water going through is hot enough. This circuit usually heats up fairly quickly, though.
+The thermostat for this zone is in the middle of the Wood Shop, right next to the (separate) air conditioner thermostat.
 == Outside air exchange ==
@@ Line 158: / Line 175: @@
 == Maintenance ==
 Some of our HVAC systems require regular maintenance.
+[[File:Boiler-1-feed.png|200px|thumb|left|The water supply arrangement on the boiler for the north shop.]]
+==== Water Level ====
+The boilers are connected to the incoming water supply in the usual way, with pressure reducing valves. The PRV for the south-side boiler has a bypass lever on it, which can be pulled up to force water in, but it is supposed to add water automatically if needed. This lever should only be pulled up for major service, like flushing the system, or if the PRV doesn't work for some reason.
+The north-side boiler's pressure reducing valve doesn't have a bypass lever. Instead, it has a separate bypass valve that can be opened to fill the boiler. As of December 2020, the PRV doesn't seem to work correctly and may need to be adjusted. If water needs to be added to the system, open the green valve under the PRV until it is topped up. Cold pressure in both boilers should be about 12 psi.
 ==== Pumps ====
-In the boiler room the two red pumps that force hot water for radiant heat in the front room and the shop area. These pumps have three ports for oil lubrication. The two ports on either side of the pump get 3 drops of oil each, the covered port over the bearing needs one strong squirt. This needs to be done annually. This was last performed 2018-01-14.
+In the boiler room the two red pumps that force hot water for radiant heat in the front room and the shop area. These pumps have three ports for oil lubrication. The two ports on either side of the pump get 3 drops of oil each, the covered port over the bearing needs one strong squirt. This needs to be done annually. This was last performed 2020-10-29.
 ==== Filter ====